a "note" is kind of a sticky to your foto, it is generated by clicking on "Actions" on the bar under the film strip. then chose "Add a Note" and voila, there is a smal square on your picture which you can edit for size and position, and insert text or another picture using the bbc code
If you chose to insert a picture, you'll have to add at least one symbol or character beside the bbc code in order for it to work. I use a point "."
You can have a look at my domino post after yours, there you'll find a note.

On the other hand, it is more user friendly to add the linking element to the description, because the translate button doesn't work in notes... I should consider changing the instructions in the group pool.